Inspiratory Phase

Definition - What does Inspiratory Phase mean?

Inspiratory phase is the term used to describe the period of the breathing cycle in which a person inhales. The period of an inspiratory phase is measured from the point at which inspiration or inhaling begins. The inspiratory phase ends when expiration or exhaling begins. Together, these two phases comprise a respiratory cycle. The timing of a person’s respiratory phases may be used to determine their breathing efficiency and to provide appropriate breathing therapies or treatments.

WorkplaceTesting explains Inspiratory Phase

Breathing involves two phases: inspiration and expiration. During inspiration, air is brought into the lungs and during expiration, it is pushed out. Inspiration may be automatic or controlled by an assistive breathing device such as a ventilator. Inspiration is initiated by the contraction of the diaphragm and the muscles surrounding the ribs. This active muscle action expands the chest cavity and the capacity of the lungs, creating an area of negative air pressure. Air from the surrounding environment then enters the lungs to achieve equilibrium. When the muscles subsequently relax, the chest cavity tightens, increasing the air pressure within the lungs, and expiration begins.